Perioperative care in an adolescent patient with heparin-induced thrombocytopenia for placement of a cardiac assist device and heart transplantation: case report and literature review

Abstract

Heparin-induced thrombocytopenia (HIT) can cause life-threatening complications following the administration of heparin. Discontinuation of all sources of heparin exposure and the use of alternative agents for anticoagulation are necessary when HIT is suspected or diagnosed. We present the successful use of bivalirudin anticoagulation in an adolescent patient during cardiopulmonary bypass who underwent both placement of a left ventricular assist device and subsequent heart transplantation within a 36-hour period. The pathophysiology and diagnosis of HIT are reviewed, previous reports of the use of direct thrombin inhibitors for cardiac surgery are presented, and potential dosing regimens for bivalirudin are discussed.

Dose estimation for bivalirudin during pediatric cardiopulmonary bypass

“…3 In healthy adults this appears to show a ceiling effect with an ACT at around 452 seconds, though longer values have been described in children and adults during bypass. 24,28,30 Other target ACT values have been reported in adults given bivalirudin, for example, a lower target of 2.5 times baseline 33,34 may reduce blood loss. There are known limitations of ACT as a coagulation test and this may not truly describe the ability of bivalirudin, at any given concentration, to inhibit thrombus formation in-vivo.…”

“…Use of adult regimens in children with upwards titration of dose using an activated clotting time (ACT) has been shown to be satisfactory, [24][25][26][27][28][29] but such manipulation of dose can be slow to attain desired effect and is prone to overdose because of time delays to achieve target drug concentration; an increase in infusion alone takes 3-5 half-lives to reach a new steady-state. There are also delays undertaking (e.g., 10 min intervals) and awaiting results of the ACT effect measure.…”

“…Practitioners currently initiate bivalirudin at 2.5 mg kg −1 h −1 in children and either titrate infusion rate or give incremental bolus drug to achieve an ACT longer than 400 s. 22,23 Consequent reported infusion rates are closer to that proposed for a target concentration of 15 mg L −1 . Argueta-Morales et al, 24 Almond et al, 25 Faella et al, 26 Bryant et al, 27 Kamata et al, 28 Dosing in neonates and infants younger than 1 year remains problematic. A bivalirudin clearance maturation profile has not been characterized and clearance may be lower than predicted from adult because renal function is immature.…”

Use of bivalirudin as a primary anticoagulant in a child during Berlin Heart EXCOR ventricular assist device support

“…The literature on bivalirudin use in children is sparse with case reports of its use during cardiopulmonary bypass, 15 in patients with HIT 16 and in a case series of patients who failed conventional antithrombotic regimen. 17 More recently, a randomized controlled trial comparing heparin and bivalirudin as anticoagulation for cardiopulmonary bypass during open heart surgery was suggestive of safety and effectiveness with no increase in postoperative bleeding or blood product requirement.…”

Pulmonary Embolism due to Heparin-Induced Thrombocytopenia (HIT): A Case Report of an 11-year-old Child Undergoing Scoliosis Surgery and Literature Review

“…heparin-coated catheters, flushing solution, plasma products, etc.) should be immediately stopped (before resolution of thrombocytopenia and without awaiting laboratory diagnosis) in children suspected to suffer from HIT according to clinical assessment or biological criteria [35]. A nonheparin anticoagulation (Danaparoid (Orgaran®, Msd, France) [12,33] or direct thrombin inhibitor (Hirudin) should be started [32][33]36].…”